Osteoarthritis (OA) is the most common rheumatic disease of the elderly, with 40 million Americans estimated to have radiological evidence of OA. A controversy exists regarding the accuracy of the established radiographic OA grading scale (Kellgren, Lawrence 1957) because it assumes a natural history of osteoarthritis which has never been validated by longitudinal studies. The most notable shortcoming of the Kellgren/Lawrence scale is that the OA status of many joints doesn't fit easily into the grading system. In this project we developed grading scales for the individual radiographic features of hand osteoarthritis (osteophytes, joint space narrowing, subchondral sclerosis, lateral deformity, and cortical collapse). We use the new scales to individually examine each of the radiographic features of hand osteoarthritis, in a prospective study of normally aging men. This methodology allows us to establish both the initial findings and the progression -- in short, the natural history of hand OA. This has demonstrated that: a) The incidence of hand OA increases with age -- men who have escaped developing OA into their later years of life are still at an increased risk. b) Hand OA progresses faster in older subjects. c) Joint space narrowing is a common early finding of hand osteoarthritis. Lone osteophytes, even very small ones, are also an early predictor of the later development of OA. A project which utilized magnetic resonance imaging was designed to establish whether MRI can visualize joint abnormalities in subjects with knee pain and normal radiographs, however our MRI was unable to distinguish early changes in OA.